Fuel cap maintenance

[alcladrv]

I recently replaced both o-rings on each fuel cap after 350 hrs. in 3 years in my -7A. Neither cap fully seals against the water when it sits out in the rain any better than before I changed the o-rings. The left side has been increasingly hard to push down the "ears" on the cap to lock it. I adjusted it to where it works a little easier.

Should I use some kind of lube on the fuel caps and o-rings? What is a good guideline to use to adjust the caps as well as possible?

Thanks,

Mike

 

[Mel]

Yes!

Lube the "O" rings regularly. Almost any lubricant will do. I use Lubriplate. I clean and re-lube them during condition inspection each year.

 

[alcladrv]

Thanks, Mel

 

[billnaz]

metal vs plastic parts

The caps on my old 6A had plastic components that failed after a years use. When I ordered replacements the new ones were metal. It's the square gasket that the cam of the latch pivots on as you close the cap. If you have older caps they may have the plastic part. You can get the name of the manufacturer from vans and order the parts direct (I'm not near the plane to look it up). New parts work great, good seal and function.

 

[gasman]

Should I use some kind of lube on the fuel caps and o-rings? What is a good guideline to use to adjust the caps as well as possible?

Thanks,

Mike

GET A TUBE OF EZ TURN FROM SPRUCE..... http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php A tube will last you a lifetime. After you lube the "O" ring then set the nut so you can install and remove the cap with a little amount of resistance.

EZ TURN will not wash off with gas and it will allow the o ring to slide up the taper of the cap as you flip the latch. YOU WILL LOVE IT.....

 

[AlexPeterson]

GET A TUBE OF EZ TURN FROM SPRUCE..... http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php A tube will last you a lifetime. After you lube the "O" ring then set the nut so you can install and remove the cap with a little amount of resistance.

EZ TURN will not wash off with gas and it will allow the o ring to slide up the taper of the cap as you flip the latch. YOU WILL LOVE IT.....

Unless you try to use them when cold.... if the temps are in the 30F and below, it gets difficult to remove the caps. Down around 10F and I had to abort fueling until getting it in a warm hangar. No way to get them off. I now use Tri-Flow around once a year and it works great, even when cold.

 

[McFly]

left side has been increasingly hard to push down the "ears" on the cap to lock it.

Just in case you haven?t tried this: Put some light oil (LPS ,10W40, 3in1,?) around the shaft where the ears attach. It will work wonders. Good luck.

 

[Griff]

Just before you reinstall the cap, dip your finger in the fuel and drip some on the cam section.
It makes for a decent lubricant, but times-a-wasting because it will evaporate quickly.

 

[Bart]

Fuel Cap Servicing

Anyone got a step by step for servicing the fuel caps. Mine get tougher to open as they age.

 

[Mike S]

Gently remove the large "O" ring from the outside of the cap.

Use a Q tip to spread a thin layer of fuel lube in the "V" groove where the "O" ring lives.

Reinstall the "O" ring.

Use the Q tip to apply a thin layer of fuel lube on the exterior of the "O" ring.

Done.

 

[flion]

It sounds too simple but you will be amazed at the difference doing the above will make. It takes about a year before I notice things getting difficult again, and then a bit of lube and I almost wonder if the caps are too loose.

 

[humptybump]

I'm not familiar with the RV-10 fuel caps but the standard (Usher flush style) caps on my RV-8 have two O-rings. There is the large visible ring and a much smaller ring inside the cap that gaskets the shaft down the middle. Given the way the cam is designed, rain water naturally wants to try to sneak down the center of the fuel cap. At each condition inspection, I disassemble the fuel caps, clean the parts of any debrise or corosion, check and lube both O-rings and replace if necessary.


http://www.aircraftspruce.com/catalog/appages/Usher_flushCaps.php

 

[BobTurner]

I assume you know the trick: after rotating the tab to the vertical, push straight down until you feel a 'click', the cap should then come out easily.